This is absolutely the fastest hard drive controller for the A500, bar none. It uses ultra-fast hidden DMA transfers to achieve speeds up to 10MB/sec. Provides you with a SCSI-2 and IDE controller, and the ability to add up to 8MB of RAM in the form of 4 Megabit ZIP chips. Has both autoconfiguring of memory and autobooting of which both can be disabled. Provides you with a 3.5" IDE connector, 50 pin internal connector and 50pin external connector. Has a GVP compatible expansion slot to add peripherals such as the GVP PC emulator card, and has it's own power supply. The unit also has "game" switches to disable various features for maximum compatibility. The LX version also includes an external power supply.